Boreskov Institute of Catalysis of the Siberian Branch of Russian ...

PP-IV-6activity in POM reaction in comparison to alumina alone, probably as a result of the increaseof oxygen mobility in support network.The Ni – support and Ni-Au interactions play very important role in the catalytic activityof these catalysts. According to TPR results, two nickel phases were observed: first - welldispersed and easy reducible NiO and second – NiO oxide strongly bonded with support. Thehigh temperature reduction effect was observed for nickel-gold catalyst after its oxidation at900°Cand it was atributed to reduction hardly reducible Ni-support structure. The spinelstructure like NiCr 2 O 4 was observed also by erlier XRD analysis.The CH 4 conversion degree for supported Ni and Ni-Au catalysts was abut 100% above700°C for POM and OSR reactions (Fig.1.). The promoting role of gold was observed during24 h POM – run reaction in the limitation of carbon deposition on bimetallic catalysts (Table1). The obtained results suggested the analogical effect for reaction of oxy-steam reforming,where stability of nickel-gold catalysts was higher than nickel catalyst. The increase of steamH 2 O addition (0,65; 0,84; 1,2%) to 5% mixture of CH 4 and O 2 increased the production ofhydrogen (Fig. 2.).CH4 conversion [%]100 a90b80c7060 d50403020100400 600 800 1000Temperature [°C]Fig. 1. The CH 4 conversion for5%Ni/Al 3 CrO 6 in POM andOSR:a,c and for 5%Ni-2%Au/Al 3 CrO 6 in POM andOSR:b,d.ConclusionsCatalystCH 4conversion[%] at900°CCarbondeposition[%] after24h POM5%Ni/Al 3 CrO 6 100 125%Ni-2%Au/Al 3 CrO 6 100 1Table 1. The CH 4 conversionand carbon deposition in POMreaction.H2 con ten t [%]876543210yzx400 600 800 1000Temper ature [°C]Fig. 2. The H 2 content at 900°Cin OSR for H 2 O steam: 1,2%-x,0,84%- y 0,65%-z.The 5%Ni/Al 3 CrO 6 , 5%Ni-2%Au/Al 3 CrO 6 catalysts are promising for partial oxidationand oxy-steam reforming of methane. The support modification of conventional aluminasupport improved the activity of catalysts, while the gold addition increased their stability andcarbon resistance in both reactions.407